Add swagger config

See strongloop/loopback-swagger#52 (comment)

Author: simonhoibm

server/config.json

@@ -2,5 +2,8 @@
   "restApiRoot": "/api",
   "host": "0.0.0.0",
   "port": 3000,
-  "url": "https://localhost:3000/"
+  "url": "https://localhost:3000/",
+  "swagger": {
+    "protocol": "https"
+  }
 }